according to canonical commutation relations proper for the Bose statistics [1]}, [2]}, [3]}
\(\left[\mathbf {\Pi }_{\Psi }[h^{\prime }],\mathbf {\Psi }[h]\right]&=&-i\delta (h^{\prime }-h),\\\left[\mathbf {\Pi }_{\Psi }[h^{\prime }],\mathbf {\Pi }_{\Psi }[h]\right]&=&0,\\\left[\mathbf {\Psi }[h^{\prime }],\mathbf {\Psi }[h]\right]&=&0.\) 
